Intrafamily Romance Satisfaction?????!?!?!?

I want to report a bug (definitely a bug) that's really uncomfortable and disturbing.

My Sim and HER OWN MOTHER were somehow able to successfully flirt.

Even worse: I have absolutely no idea how it happened. I swear to God, I wasn't even controlling them. It was a completely random and autonomous incident. Massive event, many Sims in the same place. I was controlling another Sim in the family at the time, and I got an alert that the romantic satisfaction tracking of... and... had been successfully initiated.

I immediately went to them, thinking they were both flirting with someone else.

NO.

The romantic relationship (the romance bar) was appearing in the relationship BETWEEN them.

MOTHER AND DAUGHTER.

I used a cheat to make the romance relationship disappear (it was at approximately 15 or 20% of the bar). I closed the game and repaired it. It's still at zero, but the romance bar is still there. If I open each of their profiles, there's no mention of each other, BUT in the Relationships panel, both of them have the other listed as a romantic relationship (now at zero because of the cheat I used to make it disappear).

It's frankly very awkward. I'm speechless.